Following the introduction and mass use of the power fastener driver on the factory assembly lines in the late 1930s and early 1940s, a revolution in one of the oldest mechanical inventions of man occurred. The defining change was the massive torque applied by the power fastener driver. The last decade has seen the power fastener driver come into the hands of every journeyman craftsman and a high proportion of "do-it-yourselfers" due to the proliferation of relatively inexpensive and portable power fastener drivers.
The prior art has defined the parameters of the ultimate power driver and screw as follows: 1) A bit capable of delivering and a threaded fastener capable of receiving high torque forces; 2) A driver bit possessing a large central portion capable of reliably and repeatedly transmitting high torque forces; 3) A driver bit and interfitting threaded fastener configuration subject to low cam-out (also known as low rock-out) and 4) A driver and threaded fastener interfit having high stick-fit obviating the need for a magnetized bit and its concomitant problems.